U.S. patent number 6,322,268 [Application Number 09/420,388] was granted by the patent office on 2001-11-27 for efficient fluid dispensing utensil.
This patent grant is currently assigned to Avery Dennison Corporation. Invention is credited to Dale E. Harder, Rainer Kaufmann.
United States Patent |
6,322,268 |
Kaufmann , et al. |
November 27, 2001 |
Efficient fluid dispensing utensil
Abstract
A fluid dispensing utensil, such as a writing utensil, includes
a container (20) defining a first storage area (11) for storing
fluid, a second storage area (25) and an opening therebetween, a
tip (15), a capillary conveying line (14) extending from the
opening through at least a portion of the second storage area to
the tip, and a capillary storage (16) associated with the second
storage area and in direct contact with the conveying line. A
porous shroud (28) may also be provided. Even still, the capillary
conveying line and the capillary storage may be a unitary fibrous
structure where the fibers are aligned along the longitudinal axis
defined by the tip and the opening.
Inventors: |
Kaufmann; Rainer (Delmenhorst,
DE), Harder; Dale E. (Placentia, CA) |
Assignee: |
Avery Dennison Corporation
(Pasadena, CA)
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Family
ID: |
27386916 |
Appl.
No.: |
09/420,388 |
Filed: |
October 19, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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747227 |
Nov 12, 1996 |
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630515 |
Apr 10, 1996 |
6089776 |
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150085 |
Nov 12, 1993 |
6095707 |
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Current U.S.
Class: |
401/198;
401/199 |
Current CPC
Class: |
B43K
8/02 (20130101); B43K 8/03 (20130101); B43K
8/04 (20130101); B43K 8/06 (20130101); B43K
8/08 (20130101); B43M 11/06 (20130101); A45D
40/20 (20130101) |
Current International
Class: |
B43K
5/00 (20060101); B43K 005/00 () |
Field of
Search: |
;401/198,199,196,205
;210/321.87,321.88,321.89 ;428/32,37,903 ;502/400 ;431/325 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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DE |
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1 269 010 |
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Jan 1969 |
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DE |
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1 461 588 |
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Aug 1971 |
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DE |
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2 124 298 |
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Nov 1972 |
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DE |
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1 511 395 |
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Sep 1973 |
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DE |
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2 424 918 |
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DE |
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1 808 910 |
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DE |
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3 642 037 |
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Jun 1988 |
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DE |
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3 824 941 |
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Feb 1990 |
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DE |
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PCT/DE92/00361 |
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Apr 1992 |
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DE |
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4 115 685 |
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Nov 1992 |
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DE |
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PCT/DE93/00989 |
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Oct 1993 |
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DE |
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0 210 469 |
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Feb 1987 |
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EP |
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0 461 292 |
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Jun 1990 |
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EP |
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0 405 768 |
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EP |
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EP |
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0 516 538 |
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Dec 1992 |
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EP |
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PCT/EP93/01796 |
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Jul 1993 |
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EP |
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0 899 128 |
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Mar 1999 |
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EP |
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8 76 10 |
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Sep 1966 |
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FR |
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2 528 361 |
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Mar 1983 |
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FR |
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2 737 862 |
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Feb 1997 |
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FR |
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941439 |
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Nov 1963 |
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GB |
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2 205 280 |
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Dec 1988 |
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GB |
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2 241 882 |
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Sep 1991 |
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GB |
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48-36844 |
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Feb 1967 |
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JP |
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7 701 595 |
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Aug 1978 |
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NL |
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PCT/US91/04622 |
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Jun 1991 |
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WO |
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Other References
PCT International Search Report for PCT/EP 00/05361 dated Sep. 6,
2000 for References BT thorugh BY listed above..
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Primary Examiner: Walczak; David J.
Attorney, Agent or Firm: Squire, Sanders & Dempsey,
L.L.P.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser.
No. 08/747,227, filed Nov. 12, 1996, now abandoned which is itself
a continuation-in-part of U.S. application Ser. No. 08/630,515,
filed Apr. 10, 1996, now U.S. Pat. No. 6,089, 776, which is itself
a continuation of U.S. application Ser. No. 08/150,085, filed Nov.
12, 1993, now U.S. Pat. No. 6,095,707.
Claims
What is claimed:
1. A fluid dispensing utensil, comprising:
a container defining an interior surface, the container being
separated into a first storage area for storing fluid and a second
storage area with an opening therebetween;
a tip;
a conveying line made of porous fiber bundles filling the opening
and extending from the opening through at least a portion of the
second storage area to the tip, wherein the fibers of the conveying
line are aligned with the longitudinal axis of the conveying line;
and
a capillary storage made of a porous fiber bundle and associated
with the second storage area, the capillary storage being in direct
contact with the conveying line, wherein the fibers of the storage
are aligned with the longitudinal axis of the conveying ine,
wherein the fibers of the capillary storage create larger voids
than the fibers of the conveying line.
2. The fluid dispensing utensil according to claim 1, wherein a
predetermined pore size is the largest pore size in the conveying
line.
3. The fluid dispensing utensil according to claim 2, wherein air
passes through the predetermined pore size.
4. A fluid capillary channel associated with a fluid source,
comprising:
an inlet adapted to be coupled to the fluid source;
a tip; and
a plurality of fibers bundled along a longitudinal axis from the
inlet and the tip, wherein the bundle of fibers has a varying
effective pore size, and wherein the effective pore size of the
bundle of fibers generally increases continuously and radially from
the longitudinal axis.
5. The fluid capillary channel according to claim 4, includes a
predetermined effective pore size defining a conveying line and a
storage, wherein the pore sizes equal to or smaller than the
predetermined effective pore size in the capillary channel define
the conveying line, wherein the pore sizes larger than the
predetermined effective pore size in the capillary channel define
the storage.
6. The fluid capillary channel according to claim 5, wherein air
passes through the predetermined effective pore size.
7. The fluid capillary channel according to claim 5, wherein the
predetermined effective pore size is approximately between 30
microns to 65 microns.
8. The fluid capillary channel according to claim 7, wherein a
substantial majority of the pore sizes in the conveying line are
within 5 microns of the predetermined effective pore size.
9. The fluid capillary channel according to claim 8, wherein the
smallest pore size of the conveying line is within 50 microns of
the predetermined effective pore size.
10. The fluid capillary channel according to claim 8, wherein the
largest pore size in the storage is within 60 microns of the
predetermined effective pore size.
11. The fluid capillary channel according to claim 4, wherein the
plurality of fibers are aligned along the longitudinal axis from
the inlet to the tip.
12. The fluid capillary channel according to claim 4, wherein the
fibers are made of a polyolefin material.
13. The fluid capillary channel according to claim 4, wherein the
fibers are made of a polyethylene material.
14. The fluid capillary channel according to claim 4, wherein the
plurality of fibers form a substantial cylindrical shape.
15. The fluid capillary channel according to claim 4, wherein the
plurality of fibers form a unitary conveying line and a
storage.
16. The fluid capillary channel according to claim 4, including a
conduit coupling the fluid source to the inlet of the capillary
channel.
17. The fluid capillary channel according to claim 16, wherein the
conduit has a large opening and a smaller opening, the larger
opening facing the fluid source and the smaller opening associated
with the inlet of the capillary channel.
18. An efficient fluid dispensing utensil, comprising:
a container defining an interior surface, the container being
separated into a first storage area for storing fluid and a second
storage area with an opening therebetween;
a feeder terminating at a tip; and
a unitary capillary channel associated with the second storage
area, the capillary channel having a rear end and a second end, the
rear end of the capillary channel coupled filling the opening
between the first and second storage areas, the feeder coupled to
the second end of the capillary channel, wherein the unitary
capillary channel is comprised of a plurality of fibers aligned
along a longitudinal axis between the rear end and the tip, wherein
the plurality of adjacent fibers provide porous paths along the
fibers having an effective pore size, and wherein the effective
pore size of the plurality of porous fibers generally increases
radially from the longitudinal axis;
whereby said unitary capillary channel normally acts to convey
fluid directly from said conduit to said tip through centrally
located fiber paths, and upon excess flow of fluid resulting from
overpressure in said first storage area, the fluid may be stored in
porous volumes associated with said longitudinally extending fibers
which are radially outward from said centrally located fibers.
19. The fluid dispensing utensil according to claims 18, wherein
the unitary capillary channel defines a conveying line and a
storage.
20. The fluid dispensing utensil according to claim 19, including a
predetermined effective pore size defining the largest pore size in
the conveying line, and wherein said storage includes pore sizes
greater than the predetermined effective pore size.
21. The fluid dispensing utensil according to claim 20, wherein air
passes through the predetermined effective pore size.
22. The fluid dispensing utensil according to claim 20, wherein the
predetermined effective pore size is approximately between 30
microns to 65 microns.
23. The fluid dispensing utensil according to claim 20, wherein the
smallest pore size in the conveying line is within 5 microns of the
predetermined effective pore size.
24. The fluid dispensing utensil according to claim 20, wherein the
smallest pore size of the conveying line is within 50 microns of
the predetermined effective pore size.
25. The fluid dispensing utensil according to claim 20, wherein the
largest pore size in the storage is within 60 microns of the
predetermined effective pore size.
26. The fluid dispensing utensil according to claim 20, wherein the
smallest pore size of the storage is substantially equal to or
larger than said predetermined effective pore size.
27. A combination of a conveying line and a capillary storage for
conveying liquid through the conveying line and storing any excess
liquid in the capillary storage, comprising:
a conveying line having a distribution from a smallest capillarity
to a largest capillarity, wherein between the smallest capillarity
and the largest capillarity of the conveying line is an average
capillarity, the conveying line having a proximal end and a distal
end, the distal end adapted to be in direct contact with liquid in
a storage area; and
a capillary storage having a distribution from a smallest
capillarity to a largest capillarity, wherein between the smallest
capillarity and the largest capillarity of the capillary storage is
an average capillarity, the capillary storage having an opening at
least partially through its longitudinal axis, wherein the
conveying line is adapted to be inserted into the opening of the
capillary storage and at least a portion of the capillary storage
is in direct contact with the conveying line, such that the
capillary storage only comes into contact with the liquid in the
storage area by way of the conveying line, wherein the smallest
capillarity of the conveying line is at least equal to the largest
capillarity of the capillary storage.
28. A combination according to claim 27, wherein the smallest
capillarity of the conveying line is substantially equal to the
largest capillarity of the capillary storage.
29. A combination according to claim 27, wherein the largest
capillarity of the capillary storage is greater than the smallest
capillarity of the conveying line.
30. A combination according to claim 27, wherein the smallest
capillarity of the conveying line is greater than the average
capillarity of the capillary storage, but less than the largest
capillarity of the capillary storage.
31. A combination according to claim 27, wherein the largest
capillarity of the conveying line is greater than the largest
capillarity of the capillary storage.
32. A combination according to claim 27, wherein the largest
capillarity of the conveying line forms an air passage to flow air
into the storage area to compensate for liquid leaving the storage
area.
33. A combination according to claim 27, wherein the capillary
storage is made from a porous material.
34. A combination according to claim 27, wherein the capillary
storage is made from reticulated foam ranging from hydrophilic to
hydrophobic.
35. A combination to claim 27, wherein the capillary storage is
made from polyolefins.
36. A combination according to claim 27, wherein the conveying line
is formed from fibrous materials.
37. A combination according to claim 27, wherein the proximal end
of the conveying line is adapted to associate with a tip.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to fluid dispensing
utensils and, more particularly, to a fluid dispensing utensil
which is adapted to prevent leakage.
2. Description of the Related Art
Fluid dispensing utensils are commonly used to deliver fluids such
as ink, paint, adhesives, shoe polish, lotion, medicine, perfume,
makeup, white out and food. In one type of fluid dispensing
utensil, a relatively large volume of fluid is stored in a
non-capillary container (or reservoir) where it is allowed to move
freely. Pens which incorporate such a container, for example, are
referred to as "free ink" pens. That is, the ink in the reservoir
is usually in a liquid state, and is free to move about as the
writing utensil is moved. Fluid in these utensils is transferred
from the container to the delivery end (often referred to as a tip
or a nib) via a capillary conveying line. A slight vacuum
(underpressure) relative to the atmosphere is maintained within the
container which prevents fluid in the conveying line from escaping
from the utensil until the tip is brought into contact with the
surface onto which fluid is to be dispensed. At this point, the
force of attraction of the surface and the capillary force of the
space between the surface and portions of the tip which are not in
direct contact with the surface will cause the fluid to flow from
the tip to the surface. As fluid is dispensed, air enters the
container in a controlled manner via a precisely sized air inlet
that is formed in the container and ends within the fluid. The air
replaces the fluid so as to maintain the vacuum at a relatively
constant level.
One problem associated with these dispensing devices is leakage
caused by air expansion within the container. Specifically, when
the air within the container is heated it expands. This causes the
vacuum within the container to subside and increases the vapor
pressure on the fluid. The reduced vacuum and increased vapor
pressure cause the utensil to leak through the tip when oriented in
the delivery orientation, i.e. when facing at least partially
downwardly.
In an attempt to reduce these types of leaks, some ink pens include
an overflow chamber having a capillary storage that will absorb
ink. Fountain pens, for example, include a capillary storage in the
front section and sometimes under the nib. This storage has a
capillarity that is strong enough to prevent leakage when the pen
is held in the writing position, but not so strong that it will be
filled during a normal writing operation. The capillary storage
will not receive fluid when there is substantial air expansion
within the container. As a result, these capillary storage systems
have been unable to prevent leakage from free ink pens which hold a
relatively large volume of ink and, ultimately, a relatively large
volume of air. They have also been unable to prevent the leakage
caused by relatively large amounts of air expansion in smaller
containers.
The storage capacity of existing fountain pen systems which are
able to prevent leakage during temperature fluctuations associated
with normal use is less than 2.0 milliliters. The reasons for this
limitation are as follows. The conveying tube, which transfers
fluid via capillary action, must be large enough to produce the
desired ink flow during writing. The capillary storage consists of
capillaries that must be larger than those of the conveying line.
Otherwise, the storage would normally be filled with ink and unable
to store excess ink as needed. The storage must also create enough
capillary force to hold the ink when the fountain pen is being held
vertically. Such force (which is often referred to as "capillary
height") is inversely related to the size of the capillaries. Thus,
in order to increase the volume of the storage, it is necessary to
reduce the size of the capillaries. This is not possible, however,
because the storage capillaries must be larger than those of the
conveying line, which in turn must be large enough to insure proper
ink flow. Accordingly, the volume of liquid that can be stored by
the capillary storage is limited. This limits the amount of ink
that can be stored in the reservoir.
Other pens include capillary storages configured such that the vast
majority of the pores are smaller than the air inlet and are made
of a material that is the same or substantially similar to that
which forms the conveying line. As a result, the capillary storage
will normally be completely filled with fluid and unable to receive
additional fluid when air expands within the container. One
proposed method of reducing this problem is to reduce the size of
the air inlet. The proposed method has proven to be unsuccessful,
however, due to manufacturing limitations which make it
prohibitively difficult to produce sufficiently small air inlets.
Another proposed method of reducing this problem is to increase the
size of the storage capillaries. This method has also proven
unsatisfactory because the increase in pore size decreases the
capillary height of the capillaries and reduces the amount of fluid
that can be stored therein when the pen is in the upright position.
Thus, to optimize the performance of the conveying line and the
storage capillaries, the pore sizes of the conveying line and
storage capillaries are preferably carefully controlled.
Still other pens include capillary storages that consist of a
series of radially extending fins which form capillaries
therebetween. There are a number of disadvantages associated with
the fin-type capillary storages. For example, air interferes with
the flow of ink back to the reservoir. In addition, fin-type
capillary storages take up a relatively large portion of the
overall volume of the pen, thereby substantially reducing the
amount of volume available for the ink reservoir.
Yet another problem is that the capillary storage swells as it
absorbs the excess fluid. The swelling causes the capillary storage
to push against the container wall, thereby restricting the air
within the capillary storage from releasing freely into the
atmosphere, through the surface areas where the storage member
pushes against the container wall. The trapped air within the
capillary storage, however, prevents the capillary storage from
absorbing additional excess liquid. Thus, the swelling limits the
capillary storage from absorbing to its full capacity.
OBJECT AND SUMMARY OF THE INVENTION
The general object of the present invention is to provide a fluid
dispensing utensil which obviates, for practical purposes, the
aforementioned problems in the art. In particular, one object of
the present invention is to provide a fluid dispensing utensil
which is capable of storing a relatively large volume of fluid
without leaking during periods of container air expansion. Another
object of the present invention is to provide a fluid dispensing
utensil which is relatively inexpensive and easy to manufacture.
Yet another objective is to provide a combination of pore sizes in
the conveying line and the capillary storage that will channel the
flow of fluid to the tip, and not radially to the capillary
storage. At the same time, it is important to maximize the flow
rate of fluid through the conveying line, so that ample supply of
fluid is available for writing.
In order to accomplish these and other objectives, the present
fluid dispensing utensil includes a container, a capillary
conveying line and a capillary storage in direct contact with the
conveying line. The average capillarity of the storage is generally
less than that of the conveying line, at least in the area of the
opening between the container and the rest of the utensil. In
addition, the lowest capillarity of the storage is substantially
less than that of the conveying line. That is, the largest pore
size in the storage is substantially greater than that of the
conveying line. Furthermore, the greatest capillarity of the
storage is preferably substantially equal to or less than the
lowest capillarity of the conveying line. That is, the capillary
storage preferably has very few or no pores smaller than the
largest pore of the conveying line, but no pores so large that they
cannot hold the height of liquid above the bottom of the reservoir.
Due to these features, the vast majority of the capillary storage
pores are normally free of fluid and will only store fluid during
periods of air expansion in the fluid container. As air in the
container contracts back to its original volume, fluid will be
drawn out of the storage by the conveying line and returned to the
container. The capillary conveying line may be configured such that
some of capillaries in the conveying line are relatively small and
transfer fluid, while others are relatively large and transfer air.
This allows air and liquid to flow in parallel through the
conveying line in opposite directions. In addition, the container
may be configured such that air is only able to enter the container
via the conveying line. Thus, the conveying line may be used to
regulate the amount of air flowing into the container.
It should be noted that the descriptive term "capillarity" has been
used herein to indicate the height up to which a liquid ascends
within a pore of a given diameter. The greater the height, the
greater the capillarity. In general, small size pores have greater
capillarity than the larger size pores. In other words, the term
"capillarity" is indicative of the attractive force between a
liquid and a pore.
There are a number of advantages over prior fluid dispensing
utensils associated with the present invention. The primary
advantage of the present fluid dispensing utensil lies in the fact
that it will reliably function under greater temperature
fluctuations (and resulting air expansions) than utensils which are
presently commercially available. This reliability will also extend
to greater fluid storage volumes than commercially available
utensils (10 ml or more). This improved reliability will also
extend to outside pressure variations, such as those which occur
when a utensil is on an airplane. As noted above, fluid saturates
the capillary storage in many prior dispensing utensils. This
eventually results in undesired leakage. Conversely, the capillary
storage in the present invention is substantially emptied each time
the air expansion within the container subsides, thereby preventing
the aforementioned leakage caused by full storages. In addition,
the use of the conveying line as the air inlet eliminates the need
to form a very small air inlet in the fluid container. As it is
much easier to manufacture capillary conveying lines with pores
that are often as small as one one-thousandth of an inch than it is
to form an air inlet of similar dimensions in a molded plastic
container, a utensil in accordance with the present invention is
less expensive to manufacture than prior utensils.
In one embodiment of the invention, the capillary conveying line
extends to the bottom (or rearward) area of the container and is
surrounded up to the bottom area by a tube. Fluid is unable to
enter the conveying line when the utensil is in the dispensing
orientation and the conveying line itself becomes the only source
of fluid. Thus, this arrangement provides additional protection
against leakage.
The conveying line and storage may also be in direct contact with
one another. There are a number of advantages associated with this
arrangement. For example, as the vacuum in the reservoir increases
(due to a temperature decrease) and fluid begins to drain from the
capillary storage, the capillaries in the conveying line will
absorb essentially 100% of the fluid and return it to the
reservoir. This would not occur there was a gap (and, therefore,
air) between the storage and the conveying line. First, the
conveying line capillaries could not help draw the fluid out of the
storage, as they do when in direct contact with the storage. Also,
the air would prevent the some of the fluid from entering the
conveying line. Thus, after a few air expansion cycles, utensils
with a gap will begin to leak.
The conveying line and the capillary storage may, in accordance
with another embodiment of the invention, be integrally formed; in
other words, a unitary conveying line and capillary storage may be
formed. As a result, the conveying line and storage may be
manufactured in a single processing step to further reduce
manufacturing costs.
In accordance with another advantageous aspect of the invention, an
air passage is provided between the exterior surface of the
capillary storage and the interior surface of the container. The
air passage may be provided in a variety of ways. For example, at
least a portion of the exterior surface of the capillary storage
may be surrounded by a porous shroud. Alternatively, a
substantially rigid element may be arranged between the exterior
surface of the capillary storage and the interior surface of the
container. Adequate space may also be provided by making the inner
surface of the housing rough or irregular. On the storage side, one
or more discontinuities may be formed in the exterior surface of
the storage.
The air passage is especially useful when the capillary storage is
formed from open cell polyurethane foam because certain solvents
used in marker inks can cause this type of foam to swell.
Furthermore, capillary storage formed from open cell polyurethane,
for example, swells when used with certain solvents. However, if
the capillary storage swells to the point that the storage makes
continuous contact with the interior surface of the housing, the
flow of air from the storage to will be hampered. This can cause
leakage when pressure builds within the pen because air will be
trapped within the pores in the capillary storage that are needed
for ink storage. Accordingly, the passage improves air flow within
the pen and provides an additional measure of prevention against
leakage.
Another embodiment of the present invention employs fibers that are
resistant to swelling caused by certain solvents. For example,
polyolefins, which may be any of the polymers and copolymers of the
ethylene, propylene, et al. families of hydrocarbons, such as
polyethlene or polypropylene, may be used. That is, such fibers are
resistant to swelling so that the air within the capillary storage
is free to flow from the storage.
To further minimize air within the storage from being trapped, the
fibers in the storage may be aligned along the length of the
reservoir. That is, porous fibers of the storage are aligned
parallel to conveying line. Accordingly, even if the capillary
storage does swell, the porous fibers along the side edges are open
to allow the air within the storage to flow out of the storage.
The above described and many other features and attendant
advantages of the present invention will become apparent as the
invention becomes better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the preferred embodiments of this
invention will be made with reference to the accompanying
drawings.
FIG. 1 is a cross-section view of a fluid dispensing utensil in
accordance with a preferred embodiment of the present
invention;
FIG. 2 is a diagram showing, for at least the area adjacent the
opening between the container and the capillary storage chamber,
the capillary potential of the pores in the capillary storage and
capillary conveying line plotted against the percentage of
pores;
FIG. 3 is a cross-section view of the utensil shown in FIG. 1
illustrating the manner in which air enters the container and fluid
exits the container;
FIG. 4 is a cross-section view of a fluid dispensing utensil in
accordance with another preferred embodiment of the present
invention;
FIG. 5 is a cross-section view of a fluid dispensing utensil in
accordance with still another preferred embodiment of the present
invention;
FIG. 6 is a cross-section view of a fluid dispensing utensil in
accordance with still another preferred embodiment of the present
invention;
FIG. 7 is a cross-section view of a fluid dispensing utensil in
accordance with yet another preferred embodiment of the present
invention;
FIG. 8 is a perspective view of a capillary storage shroud in
accordance with another preferred embodiment of the present
invention;
FIG. 9 is a perspective view of a capillary storage shroud in
accordance with another preferred embodiment of the present
invention;
FIG. 10 is a cross-section view of a fluid dispensing utensil
including a shroud;
FIG. 11 is a cross-section view of a hollow feeder tube which may
be used in conjunction with the utensil shown in FIG. 10;
FIG. 12 is a cross-section view of a fluid dispensing utensil in
accordance with still another preferred embodiment of the present
invention;
FIG. 13 is a cross-section view of a fluid dispensing utensil in
accordance with yet another preferred embodiment of the present
invention;
FIG. 14 is a cross-section view of a fluid dispensing utensil in
accordance with another preferred embodiment of the present
invention;
FIG. 15 is a cross-section view of a fluid dispensing utensil in
accordance with yet another preferred embodiment of the present
invention;
FIG. 16 is an enlarged cross-section view of a unitary conveying
line and storage shown in FIG. 15, in accordance with another
preferred embodiment of the present invention;
FIG. 17 is a cross-sectional view of the unitary conveying line and
storage shown in FIG. 16 along 17--17;
FIG. 18 is a perspective view of a conveying line and a storage
with pores aligned longitudinally; and
FIG. 19 is a diagram showing an exemplary relationship of pore
sizes between a conveying line and storage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following is a detailed description of a number of preferred
embodiments of the invention. This description is not to be taken
in a limiting sense, but is made merely for the purpose of
illustrating the general principles of the invention.
As shown by way of example in FIG. 1, a preferred embodiment of the
present invention (generally represented by reference numeral 10)
includes a housing 20 consisting of a container 11 for storing
fluid 13 and an overflow chamber 25. Container 11 and overflow
chamber 25 may be separated by a partition 21. It is to be
understood, however, that partition 21 is only an exemplary
representation of the boundary between the container and overflow
chamber. An alternate boundary is discussed below with respect to
FIG. 7. Container 11 may also be embodied in any suitable manner,
either as an integral part of housing 20 or as a separate element
connected to the housing. A tip 15 extends from one end of housing
20 in a known manner. An inlet 22 allows air to flow freely in to
and out of overflow chamber 25.
Partition 21 includes an opening 12 which, as shown by way of
example in FIG. 1, is closed by a capillary conveying line 14. The
conveying line extends from opening 12 to tip 15 and is in direct
contact with a capillary storage 16. The average capillarity of
capillary storage 16 is smaller than the average capillarity of
conveying line 14. Although the capillary storage is arranged about
the periphery of capillary conveying line 14 in the embodiment
shown in FIG. 1, there is no requirement that it extend all the way
around the conveying line. Also, the strict separation of capillary
storage 16 and conveying line 14 shown in FIG. 1 is not absolutely
necessary. With respect to assembly when the conveying line 14 and
storage 16 are separate elements, assembly may be performed by
wrapping a sheet of storage material around the conveying line and
then heat sealing the abutting ends of the wrapped sheet to one
another.
The ink in the reservoir is held in place by an
"underpressure"(slight vacuum) of the air above the ink, which
counteracts the force of gravity pulling on the ink inside the
utensil (the head pressure). This underpressure controls the ink
flow out of the marker, like a straw full of liquid with a finger
over the top which creates a slight vacuum within the straw to hold
the liquid therein. The underpressure depends on many factors, such
as, the liquid's viscosity, specific gravity and surface tension,
the diameter of the tube, the size of the opening at the bottom of
the tube, the surface energy of the tube, atmospheric pressure and
even temperature all affect how well the liquid wants to stay where
it is. The relationship of the above factors as it relates to flow
of liquid is listed in the table below.
Property High Low Fluid: Viscosity resists flow flows freely
Specific gravity flows freely resists flow Surface tension resists
flow flows freely Tube: Diameter flows freely resists flow Bottom
opening flows freely resists flow Surface energy resists flow flows
freely Atmosphere: Pressure resists flow flows freely Temperature
flows freely resists flow Gravity flows (constant force while on
earth)
As illustrated by way of example in FIG. 3, one way of controlling
underpressure is by controlling the largest pore size in the
conveying line 14 to control the airflow into the reservoir. For
example, during writing, the finer capillaries of the conveying
line 14 transfers fluid 13 to the tip. As fluid 13 leaves the
reservoir, however, underpressure will increase (this is double
negative, so the absolute pressure within the reservoir will
decrease). But at the same time, the underpressure will want to
remain constant. Thus, to compensate, air 23 is drawn into the
container 11 (reservoir) through the largest pore size in the
conveying line 14. It has been observed that, under normal writing
conditions, air 23 generally enters through a single largest pore
in the conveying line 14. Although, in extreme conditions where the
change in underpressure is rapid, air may also enter through the
next largest pore in the conveying line 14. As such, each
individual marker will have its own individual underpressure, due
to the variability of the largest pore size from one conveying line
to another.
Changes in atmospheric pressure or temperature can affect
underpressure. When the external temperature or altitude increases,
the underpressure inside the marker decreases (again, this is a
double negative, so the absolute pressure inside the marker
increases, though still is below ambient). Since the underpressure
wants to remain constant, the air volume inside the reservoir
increases until the underpressure stabilizes. Because the air
volume increases, "excess" liquid will flow down and out of the ink
reservoir, i.e. leak out of the writing instrument. To prevent such
leakage of liquid, the present invention incorporates an overflow
reservoir (storage) that will capture the ink when it needs to, but
willingly returns the excess liquid back to the reservoir when the
temperature returns to its original temperature.
Similarly, if the temperature or altitude decreases, the
underpressure inside the marker increases as well, and any liquid
inside the storage will be sucked back into the container 11. If
the increase in underpressure is greater than the volume of liquid
in the storage, small bubbles of air will be sucked into the marker
until the underpressure stabilizes.
As such, the present invention controls air flow to control liquid
leakage. That is, liquid flow is an effect of air flow in this
system by maintaining underpressure within the reservoir. As
discussed above in FIG. 3, air flows through the largest pore in
the conveying line 14 and ink flows through the remainder of the
smaller pores. Since, it is air flow through the largest pore size
in the conveying line 14 that regulates underpressure which
regulates how well liquid is held inside the writing instrument,
the largest pore size in the conveying line should be carefully
selected. For example, if the largest pore size is too large, air
will easily flow into the reservoir, the underpressure will be too
low, and the marker will not be able to hold very much liquid.
Consequently, most of the liquid will flow into the storage, or
even out of the marker if the storage is full. On the other hand,
if the largest pore size is too small, air flow is restricted, and
unable to maintain the underpressure at a constant level as the
liquid leaves the reservoir. Consequently, the underpressure will
increase, and eventually restricting the liquid within the
reservoir from leaving, resulting in a poor writing quality. Thus,
to optimize the performance of the writing utensil, the largest
pore size in the conveying line cannot be too large or too small,
so that the underpressure within in the reservoir can be
maintained.
To further optimize the performance of the writing utensil, the
smallest pore size in the overflow reservoir (storage) also needs
to be carefully selected. As discussed above, capillarity of same
materials with smaller pore sizes have higher drawing power to a
liquid than larger pore sizes. Since, the storage should only
receive excess fluid, the pore sizes in the storage in general
should be greater than the pore sizes in the conveying line.
However, as the pore sizes increase, the capillarity pull
decreases. That is, in the writing position where the writing
instrument is held in substantially vertical position, gravity acts
upon the liquid absorbed in the storage. Naturally, the greater the
height of liquid in the storage in the vertical position, the
greater the pulling weight on the liquid within the pores.
Consequently, if the pore sizes are too big, then the downward
force of gravity will overcome the capillarity force from the
bigger pores, and these bigger pores will be unable to hold the
excess liquid. Thus, the pore sizes in the storage also needs to be
carefully selected.
Following is the relative capillarity relationship of the
components that make up the writing utensil, along with the
air.
Air (anywhere in the system) capillarity = zero Storage capillarity
= medium Conveying Line capillarity = high Nib capillarity = higher
Paper capillarity = highest
Again, liquid flows from an area of low capillarity to an area of
higher capillarity. When writing, the paper having higher
capillarity than the nib pulls ink from the nib, Likewise, nib
having higher capillarity than the conveying line, pulls the liquid
from the conveying line. If there is any ink in larger pores in the
storage, they will drain too. In other words, all the liquid flows
onto the paper.
During times of decreasing underpressure, (i.e., absolute pressure
increases) liquid flows out of the utensil. It flows into all the
areas of the marker, filling the areas with the highest capillarity
first. Once they fill up, the ink flows into the area of lower
capillarity, until it too fills up. Only if the storage were full
(lowest capillarity except for air) would the ink have nowhere else
to go, and a droplet might form. In the case of our design,
however, the volume of storage is adequate to handle all changes in
temperature and pressure which may reasonably be encountered. A
mixture of porous and/or fibrous materials may be provided which
have a distribution of larger and smaller capillaries, such as the
distribution shown in FIG. 2, within the material forming the
capillary storage and conveying line. As the conveying line is
formed from a number of small capillaries that are connected to one
another, the same amount of fluid flow may be achieved with a
larger single capillary tube. This advantageously allows the size
of the storage capillaries to be reduced and the length of the
storage increased, thereby increasing storage volume.
The conveying line and storage may be formed from any suitable
material. However, such material should have a capillary structure
and is preferably a porous material. Exemplary conveying line
materials include fibrous materials, ceramics and porous plastics
such as that manufactured by Porex in Atlanta, Ga. One exemplary
fiber material is an acrylic material identified by type number
C10010 that is manufactured by Teibow Hanbai Co. Ltd. This company
is located at 10-15 Higashi Nihonbashi 3 Ohome, Chou-Ku, Tokyo 103,
Japan. Additionally, the conveying line may also consist of a
porous plastic tube which runs from the container to the tip. The
end of tube adjacent the tip is closed and regulates air flow into
the container. Exemplary storage materials include reticulated
foam, which may range from hydrophilic to hydrophobic. The last
mentioned type of foam may be used with non-water based liquids.
The choice of foam depends, of course, on fluid type. One
preferable reticulated foam is Bulpren S90 manufactured by
Recticel, which is located at Damstraat 2, 9230 Wetteren, Belgium.
Bulpren S90 is an open cell polyurethane foam based on polyester
which averages 90 pores per inch. This foam is compressed to 1/3 of
its original volume at 180 degrees Celsius to form the storage.
This volume is maintained after the foam cools. Other storage
materials include ceramics and porous plastics. Furthermore, to
minimize swelling of the storage, fibrous material resistant to
swelling caused by certain solvents are preferably used. For
example, polyolefins, which are any of the polymers and copolymers
of the ethylene, propylene, et al families of hydrocarbons may be
used, such as polyethlene or polypropylene. Such fibers are
resistant to swelling so that the air within the storage 16 are not
trapped within the storage. Furthermore, these fibers create porous
paths by being bundled together, which permits air and liquid to
flow. Fibers with lower density have greater porosity, lower
capillarity, and bigger pore sizes. On the other hand, fibers with
higher density have lower porosity, greater capillarity, and
smaller pore sizes.
The conveying line is press-fit into container opening 12 and
provides the only path by which air can enter the otherwise closed
fluid container 11. As a result, air flow into the container may be
regulated with the conveying line. Specifically, as illustrated in
FIG. 3, the finer capillaries of conveying line 14 transfer fluid
13 to the tip. The larger capillaries allow air 23 to enter the
fluid container. At a minimum, air will enter through the largest
capillary in the conveying line. The size of the larger pores which
transport air and the amount that these pores are compressed during
the press-fitting process will ultimately dictate the amount of air
flow into the container. Container opening 12 and the press-fit
portion of conveying line 14 are, therefore, one of the control
mechanisms that regulate the flow of air into the container. Other
control mechanisms include the capillarity of the conveying
line.
As illustrated by the exemplary capillarity distribution shown in
FIG. 2, the majority of storage 16 has a capillarity that is less
than that of conveying line 14. In other words, the majority of the
pores in storage 16 are larger than the majority of the pores in
conveying line 14. There may be, however, a small percentage of
pores in the storage that are smaller than or the same size as the
largest air transporting pore in the conveying line. This portion
of the storage is represented by the overlapping area 26 of the
curves shown in FIG. 2. The few relatively small pores in the
storage will normally be filled with fluid, while the larger pores
will remain in a fluid-free state until there is air expansion
within container 11. Advantageously, the diameter of the biggest
pores of the conveying line is less than the average diameter of
the pores of the storage.
When air expansion takes place within the container 11, a portion
of the fluid in the container will be transferred through opening
12 and conveying line 14 into the normally fluid-free portions of
capillary storage 16. In other words, capillary storage 16 receives
the "excess" fluid and prevents uncontrolled leakage of the fluid
from tip 15, or any other portion of the utensil. The "excess"
fluid in capillary storage 16 will return to container 11 through
conveying line 14 when the pressure in the container subsides. This
process is repeated whenever temperature fluctuations, for example,
cause air volume fluctuations within the container. As the fluid
stored in capillary storage 16 is always returned to container 11,
the capillary storage will not already be filled to capacity when
there is an air expansion. Also, even though conveying line 14 is
continuously wetted with fluid, at least in the area of opening 12,
air cannot interrupt the return of the fluid to the container as
long as there is fluid in the capillaries of the storage 16 which
are larger than the largest pore in the conveying line 14.
Although the illustrated tip is an integral portion of conveying
line 14, the present invention is not limited to such a
configuration. The tip may also be a separate structural element,
such as a stamp tip, foam tip, roller ball, or razor tip. Also, the
size of the tip may be varied, even when the conveying line and tip
are unitary, as applications require. Where the tip is formed from
a porous material, its pores should be smaller than those of the
conveying line in order insure that the fluid in the conveying line
will toward the tip during dispensing.
To further optimize the performance of the writing utensil, FIG. 19
illustrates by way of example preferred relationship of pore sizes
between the conveying line 14' and the storage 16'. Mark "Y"
represents the largest pore size in the conveying line 16', and the
preferred lower limit as to the smallest pore size in the storage
16'. Also, as discussed above, it is the largest pore size in the
conveying line 14' that regulates underpressure. Preferably, no
pores in the storage 16' are smaller than the largest pore in the
conveying line 14'. That is, the transition in pore sizes from the
storage 16' to the conveying line 14' may be continuous with the
smallest pore size in the storage 16' preferably being slightly
bigger than the largest pore size in the conveying line 14', or not
overlapping to a significant extent. This relationship in pore
sizes between the conveying line 14' and the storage 16' optimizes
performance of the pen because the storage only absorbs the excess
liquid during periods of decreased underpressure within the
reservoir (absolute pressure increases), but releases the liquid
back to the conveying line 14' when the underpressure increases
again (absolute pressure decreases). This way, under normal writing
conditions, most, if not all of the fluid is delivered to the tip
15, and not the storage 16'. Preferably, the largest pore size in
the conveying line 14', indicated by the mark "Y" on FIG. 19, is in
the approximate range of 30 microns to 65 microns.
It should be noted, however, due to the manufacturing variance,
there may be an overlap of pore sizes between the conveying line
14' and the storage 16'. That is, there may be some overlap such as
plus or minus 5 microns in the pore sizes of the conveying line 14'
and the storage 16'. When the pore sizes overlap between the
conveying line 14' and the storage 16', some of the liquid will be
stored in the storage 16' and not delivered to the tip 15. This
condition, although not representing optimal performance of the
writing utensil is within the scope of the present invention.
Additionally, due to the tolerance there may be a gap between the
pore sizes of the conveying line 14' and the storage 16', i.e., the
transition of pore sizes from the storage 16' to the conveying line
14' is not continuous as illustrated in FIG. 19. Under this
condition, excess fluid will not be most efficiently absorbed by
the storage, however, this condition too is within the scope of the
present invention.
Another objective of the present invention is to deliver consistent
flow of liquid to the tip 15 for high quality writing. However, in
situations where the writing utensil is used continuously or in
fast strokes, the flow rate of the liquid to the tip 15 may be
insufficient to supply enough liquid for high quality writing. In
this regard, as explained below, the distribution of pore sizes
within the conveying line 14' in FIG. 19 illustrates an exemplary
graph that improves the flow rate of liquid in the conveying line
14'.
The flow rate of liquids in the conveying line 14 to a large degree
depends on the pore size. For example, flow rate through the
conveying line 14' increases as a function of the fourth power of
the radius of the pore; this means, increasing the pore size
greatly increases the flow rate. In other words, as pore sizes
increase, the density of pores in the conveying line 14' decrease,
so that there is less resistance to flow of liquid. But increasing
the pore size decreases the capillarity of the pore. The
capillarity of the pore, however, is only a factor when the pore
goes from dry to wet, but once the pore gets wet, the capillarity
force is not a significant factor and it becomes a dynamic
measurement. That is, capillarity, the attractive force of liquid,
is only a factor when the pore is dry; but once the pore is wet,
the pore is simply a channel for the liquid to flow therethrough.
However, once the pore gets dry again, then the capillarity comes
into play.
Accordingly, as illustrated by way of example by side 100 in FIG.
19, a large percentage of the pores in the conveying line 14' are
almost big as the biggest pore in the conveying line 14',
represented by the mark "Y". This way, once these pores get wet,
flow rate is maximized to provide ample amount of liquid to the tip
15. In this regard, to maximize the flow rate of liquid in the
conveying line 14', the distribution of pore sizes between the
biggest pore size "Y" and the smallest pores size "Z" in the
conveying line are preferably narrow, with the majority of the pore
sizes only slightly smaller than the biggest pore size "Y." Here,
the difference between "Y" and "Z" may be 50 microns depending on
the manufacturing tolerance. However, a distribution range that is
less than 5 microns is preferred, i.e., difference between "Y" and
"Z" is less than 5 microns. This way, majority of the pores in the
conveying line are only slightly smaller than "Y."
It should be noted that narrowing the distribution range of the
pore sizes will generally increase the peak 102 representing the
percentage of pores for the graph 14'. For example, a conveying
line 14' having a distribution range of 40 microns may have a peak
102 in the range of 30% to 40%. However, the peak 102 may increase
as the distribution range is further narrowed. Alternatively,
having a peak 102 that is substantially flat, i.e., graph 14' that
is substantially rectangular, will lower the peak 102 to a lower
percentage.
With regard to the distribution of pores in the storage 16'; as
discussed above, the pore sizes in the storage cannot be so big
that they cannot hold the excess liquid. However, the size of the
pores should be also balanced to maximize the pore volume. The pore
volume is the amount of pore spaces available in the storage to
hold a certain volume of liquid. The pore volume can be increased
by either increasing the pore sizes within the storage or
increasing the size of the storage itself. The later is less
desirable because increasing the size of the storage increases cost
of manufacturing and requires bigger construction of the writing
utensil. Thus, it is preferred that the pore sizes in the storage
are balanced instead, so that the pores are small enough to hold
excess liquid, yet big enough to maximize pore volume.
In this regard, graph 16' illustrated by way of example in FIG. 19
provides such balance in storage pore sizes as discussed above.
Here, mark "X" represents the biggest pore size in the storage 16'.
Exemplary difference between "X" and "Y", may be approximately 60
microns. Here, the peak 104 for the graph 16' is approximately 30%
to 40% of pores. For example, if the peak 104 represented 95
microns along the horizontal axis for pore size, and 35% for the
vertical axis, then that would mean that 35% of the pores are 95
microns in the storage. Preferably, the difference between points
"X" and "Y" is approximately 25 microns.
Turning to the exemplary embodiments illustrated in FIGS. 4 and 6,
conveying line 14 may be configured such that it extends into area
19 near container bottom 18. In these embodiments, the capillary
storage and the capillary conveying line are enclosed by a tube 24.
The tube provides additional protection against unwanted leakage.
When the utensil is in the dispensing orientation, i.e., with the
tip facing downwardly, the flow of fluid from the container to the
conveying line is interrupted. The interruption occurs because
there will not be any fluid in area 19, the only area from which
fluid can transferred to the conveying line. The conveying line
itself is essentially the only source of fluid.
The embodiment shown in FIG. 4 differs slightly from the embodiment
shown in FIG. 6. Specifically, in the embodiment shown in FIG. 4,
capillary storage 16 and capillary conveying line 14 are separate
structural elements and the conveying line extends into bottom area
19. In the embodiment shown in FIG. 6, a mixture of porous
materials having the requisite combination of capillary sizes form
a unitary capillary storage 16 and conveying line 14.
In the exemplary embodiment shown in FIG. 5, conveying line 14 and
capillary storage 16 define a unitary structural element similar to
that shown in FIG. 6. In this embodiment, however, rear portion 140
of the integral conveying line and capillary storage is tapered so
that it may be received in opening 12. In order to ensure that
there is a sufficient amount of fine, fluid transferring
capillaries in the container opening, this portion of the combined
conveying line/storage may be pinched together at the opening in a
defined manner. Rear portion 140 may also be provided as a separate
element that is connected to the capillary storage.
As shown by way of example in FIG. 7, capillary conveying line 14'
may be configured such that it includes a radially extending
portion that separates the container from the overflow chamber. The
conveying line and radially extending portion fill the opening
between the container and the overflow chamber. The pores in the
radially extending portion may be substantially similar to those in
the conveying line and allow air to pass, but block the flow of
fluid. As a result, the radially extending portion may be used to
regulate the flow of air into the container.
Referring to FIGS. 8-10, a porous shroud, such as shrouds 28 and
30, may be placed in an exemplary utensil 32 (such as a pen) in the
manner shown in FIG. 10. Exemplary utensil 32 includes a housing 34
divided into a container 36 and a chamber 38 by a partition 40. A
conveying line 42, which may be of the solid type described above
or a hollow porous plastic conveying line (or tube) such as that
shown in FIG. 11, extends from the container 36 through the chamber
38 to a tip 44. Use of a hollow plastic feeder tube decreases flow
resistance between the container 36 and the tip 44. A capillary
storage 46 within the chamber 38 is in direct contact with the
conveying line 42. A porous shroud (exemplary shroud 28 is shown)
surrounds the capillary storage 46 and prevents the storage from
expanding to the point at which it makes continuous contact with
the inner wall of the housing 34, thereby forming an air gap 48.
The air gap 48 provides a passage that allows air to flow out of
the utensil through an inlet 49 when pressure within the container
36 rises and liquid is forced from the container through the larger
capillaries in the conveying line 42. As shown FIG. 10, the inner
wall of the housing 34 in the area of the chamber 38 tapers
inwardly near the tip 44. The storage 46 and surrounding shroud 28
may be press fit into the overflow chamber. Of course, the press
fit is not air-tight.
The porous shroud may take a variety of forms and be composed of
any material which will both resist swelling of the capillary
storage 46 and allow to air flow therethrough. For example,
exemplary shroud 28 may be formed from a number of porous materials
including, but not limited to nylon mesh, fabrics, and papers. The
fabrics may be adhesive bonded to the storage material prior to
shaping the capillary storage around the conveying line. Exemplary
shroud 30 is formed from plastic and includes perforations 30a.
As shown by way of example in FIGS. 12-14, an air passage may be
formed between the capillary storage and the interior of the
housing by creating irregular surfaces therebetween. The irregular
surfaces prevent the capillary storage from making continuous
contact with the interior surface of the housing when the storage
swells, thereby insuring that there will be a gap to accept air
from the storage. Referring more specifically to the exemplary
utensil 50 shown in FIG. 12, the capillary storage 52 is
substantially star-shaped and has a series of depressions 54 formed
therein. Exemplary utensil 56, which is shown in FIG. 13, includes
a series of longitudinal ribs 58 which extend inwardly from the
inner surface of the housing 60. The exemplary utensil 62 shown in
FIG. 14 includes a series of longitudinally extending rods 64 that
are inserted between the housing 66 and the capillary storage 68.
Rods 64 may be replaced by capillary tubes. Adequate space may be
provided by simply making the inner surface of the housing rough or
irregular.
In addition to the methods of preventing capillary storage swelling
described above, foams that are resistant to the swelling caused by
certain solvents, such as polyethylene foam, may be employed if
they possess the other necessary properties. The capillary storage
may also be formed from alternate materials (that have the
requisite capillarity) such as standard marker filler materials and
porous plastics. Referring back to FIG. 5, an enlarged view of the
unitary conveying line 14 and capillary storage 16 is illustrated
by way of example in FIGS. 15 and 16, with the smallest pore size
near the center, and the pore sizes generally increasing radially.
Note that in FIGS. 15 and 16, the conveying line and the storage
are referred to as 14' and 16', respectively; to illustrate another
exemplary distribution of pore sizes between the conveying line 14'
and storage 16', as shown in FIG. 19. FIG. 17 illustrates an
exemplary cross-sectional view of distribution of the pore sizes in
the unitary conveying line 14' and capillary storage 16', which is
consistent with the, shown in FIG. 19. Note that the distinction
between the conveying line 14.gtoreq. and the capillary storage 16'
is determined by the predetermined pore size "Y". That is, in this
embodiment, the pore sizes smaller than "Y" are categorized as the
pores in the capillary storage 16', and pore sizes equal to or
greater than "Y" are categorized as the pores in the conveying line
14'.
As discussed earlier, one of the objectives of the present
invention is to deliver most if not all of the liquid to the tip by
ensuring that the storage only receives "excess" liquids. In this
regard, as illustrated by way of example in FIG. 16, a piercing
conduit 150 is shown which funnels the fluids from the reservoir to
the center of the unitary channel 153. The piercing conduit 150 has
a first opening 154 that is larger than a predetermined second
opening 156. The first opening 154 seals the opening 12, and the
predetermined second opening 156 is associated with the unitary
capillary channel 14', 16'. The piercing conduit 150 in this
embodiment is shaped like a funnel to optimize (minimize resistance
to) the flow of fluid from the reservoir to the unitary channel
152.
Preferably, the predetermined second opening 156 is substantially
associated with the conveying line 14' as defined above; that is,
the fluids through the predetermined opening 156 preferably only
wets the pores in the conveying line 14'. Here, since the pores in
the conveying line 14' are smaller than the pores in the storage,
only excess fluids will be absorbed by the pores in the storage; at
the same time, since majority of the pores are almost big as the
biggest pore size "Y", the flow rate through the conveying line 14'
is optimized.
Also, as illustrated by way of example in FIGS. 5 and 15, the
fibers in the storage 16 are aligned parallel to conveying line 14
to allow air within the storage 16 to freely exchange with the
atmosphere even after the capillary storage swells. Here, since the
fibers in the storage are aligned with the conveying line 14, the
openings of the storage fibers are exposed on the surface areas 157
and 158 of the storage 16. As such, since the surface areas 157 and
158 do not come in contact with the container wall, the air within
the storage fibers are free to flow out of the storage.
Yet another embodiment is illustrated by way of example in FIG. 18.
Here, unlike the unitary channel member 152 shown in FIG. 16, a
separate conveying line 14' and a storage member 16' are shown.
Consistent with the preferred distribution of pore sizes shown in
FIG. 19, mark "Z", which represents the smallest pore size the
conveying line 14' is preferably located along the center line of
the conveyor line 14'. From the center of the conveying line 14',
the pore sizes preferably increase radially with the largest pore
size preferably located along the surface of the conveyor line 14',
represented by mark "Y".
With regard to the storage 16', it has an opening 160 to receive
the conveying line 14'. The smaller pore sizes of the storage 16'
are preferably near the surface of the opening 160. Accordingly,
the larger pore sizes of the conveying line 14' are preferably in
direct contact with the smaller pore sizes of the storage 16'. The
direct contact between the conveying line 14' and the storage 16'
is generally represented by mark "Y" in FIG. 19. Again, the pore
sizes in the storage 16' increase radially with the larger pore
sizes preferably on the exterior surface of the storage 16', with
the biggest pore size represented by mark "X". When assembled, the
conveying line 14' is preferably fit snugly into the storage member
16' without any gaps between the conveying line 14' and the storage
16'.
The conveying line 14' may also vary in length, so that the end 162
may extend from the storage 16'. The extending end 162, for example
may be press fitted into container opening 12 and provide the only
path by which air can enter the otherwise closed flow container 11.
Alternatively, the end 162 may be flush against the back end of the
storage member 16', there the piercing plug 150 may be coupled to
the end 162 to deliver the fluid from the container 11.
Additionally, the conveying line 14' may also extend from the
storage 16' and still further extend outside of the container 10 to
form a tip 15.
With regard to the above embodiments illustrated in FIGS. 15 to 17,
both the unitary and the separate conveying line and storage may be
obtained from Porex Technologies, located at 500 Bohanon Road,
Fairbum, Ga. 30213, and also from Filtrona Richmond, located at
8401 Jefferson Davis HWY., Richmond, Va. 23237.
With respect to the fluid itself, the present invention is capable
of storing and dispensing a variety of fluids. For example, where
the utensil is to be used as a pen, then ink is used. Other fluids
include deodorant, perfume, medicines such as acne medicine, balms,
lotions, makeup, lipstick, paint, adhesives (whether
microencapsulated or not), white out, shoe polish and food stuffs.
In order to accommodate these different types of fluids, the pore
size and pore volume of the conveying line and storage must be
varied in accordance with the viscosity and particle size of the
fluid. For example, when the fluid is a typical writing fluid, the
diameters of the capillaries (or pores) in the conveying line may
range from 0.01 mm to 0.05 mm and the capillary (or pore) diameters
in the storage may range from 0.02 mm to 0.5 mm, with a
distribution similar to that shown in FIG. 2. Pore sizes and
volumes are increased for larger particle sizes and higher
viscosities and, conversely, are reduced for smaller particle sizes
and lower viscosities.
Although the present invention has been described in terms of the
preferred embodiment above, numerous modifications and/or additions
to the above-described preferred embodiments would be readily
apparent to one skilled in the art. For example, the utensil may be
of the "break seal to initiate" variety. Such utensils include a
stopper that prevents fluid from entering the conveying line until
the consumer is ready to use the utensil for the first time. This
keeps the both the fluid and the conveying line fresh. Another
exemplary modification is the addition of a secondary reservoir
located near the tip. Such a reservoir could have a capillarity
similar to that of the conveying line and would increase the amount
of fluid available during dispensing. It is intended that the scope
of the present invention extends to all such modifications and/or
additions and that the scope of the present invention is limited
solely by the claims set forth below. Also, it is applicant's
intention that the claims not be interpreted in accordance with the
sixth paragraph of 35 U.S.C. .sctn.112 unless the term "means" is
used followed by a functional statement.
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